query-string
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    7.0.1 • Public • Published

    query-string

    Parse and stringify URL query strings





    Install

    $ npm install query-string
    

    Not npm install querystring!!!!!

    This module targets Node.js 6 or later and the latest version of Chrome, Firefox, and Safari.

    Usage

    const queryString = require('query-string');
    
    console.log(location.search);
    //=> '?foo=bar'
    
    const parsed = queryString.parse(location.search);
    console.log(parsed);
    //=> {foo: 'bar'}
    
    console.log(location.hash);
    //=> '#token=bada55cafe'
    
    const parsedHash = queryString.parse(location.hash);
    console.log(parsedHash);
    //=> {token: 'bada55cafe'}
    
    parsed.foo = 'unicorn';
    parsed.ilike = 'pizza';
    
    const stringified = queryString.stringify(parsed);
    //=> 'foo=unicorn&ilike=pizza'
    
    location.search = stringified;
    // note that `location.search` automatically prepends a question mark
    console.log(location.search);
    //=> '?foo=unicorn&ilike=pizza'

    API

    .parse(string, options?)

    Parse a query string into an object. Leading ? or # are ignored, so you can pass location.search or location.hash directly.

    The returned object is created with Object.create(null) and thus does not have a prototype.

    options

    Type: object

    decode

    Type: boolean
    Default: true

    Decode the keys and values. URL components are decoded with decode-uri-component.

    arrayFormat

    Type: string
    Default: 'none'

    • 'bracket': Parse arrays with bracket representation:
    const queryString = require('query-string');
    
    queryString.parse('foo[]=1&foo[]=2&foo[]=3', {arrayFormat: 'bracket'});
    //=> {foo: ['1', '2', '3']}
    • 'index': Parse arrays with index representation:
    const queryString = require('query-string');
    
    queryString.parse('foo[0]=1&foo[1]=2&foo[3]=3', {arrayFormat: 'index'});
    //=> {foo: ['1', '2', '3']}
    • 'comma': Parse arrays with elements separated by comma:
    const queryString = require('query-string');
    
    queryString.parse('foo=1,2,3', {arrayFormat: 'comma'});
    //=> {foo: ['1', '2', '3']}
    • 'separator': Parse arrays with elements separated by a custom character:
    const queryString = require('query-string');
    
    queryString.parse('foo=1|2|3', {arrayFormat: 'separator', arrayFormatSeparator: '|'});
    //=> {foo: ['1', '2', '3']}
    • 'bracket-separator': Parse arrays (that are explicitly marked with brackets) with elements separated by a custom character:
    const queryString = require('query-string');
    
    queryString.parse('foo[]', {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|'});
    //=> {foo: []}
    
    queryString.parse('foo[]=', {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|'});
    //=> {foo: ['']}
    
    queryString.parse('foo[]=1', {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|'});
    //=> {foo: ['1']}
    
    queryString.parse('foo[]=1|2|3', {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|'});
    //=> {foo: ['1', '2', '3']}
    
    queryString.parse('foo[]=1||3|||6', {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|'});
    //=> {foo: ['1', '', 3, '', '', '6']}
    
    queryString.parse('foo[]=1|2|3&bar=fluffy&baz[]=4', {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|'});
    //=> {foo: ['1', '2', '3'], bar: 'fluffy', baz:['4']}
    • 'none': Parse arrays with elements using duplicate keys:
    const queryString = require('query-string');
    
    queryString.parse('foo=1&foo=2&foo=3');
    //=> {foo: ['1', '2', '3']}
    arrayFormatSeparator

    Type: string
    Default: ','

    The character used to separate array elements when using {arrayFormat: 'separator'}.

    sort

    Type: Function | boolean
    Default: true

    Supports both Function as a custom sorting function or false to disable sorting.

    parseNumbers

    Type: boolean
    Default: false

    const queryString = require('query-string');
    
    queryString.parse('foo=1', {parseNumbers: true});
    //=> {foo: 1}

    Parse the value as a number type instead of string type if it's a number.

    parseBooleans

    Type: boolean
    Default: false

    const queryString = require('query-string');
    
    queryString.parse('foo=true', {parseBooleans: true});
    //=> {foo: true}

    Parse the value as a boolean type instead of string type if it's a boolean.

    .stringify(object, options?)

    Stringify an object into a query string and sorting the keys.

    options

    Type: object

    strict

    Type: boolean
    Default: true

    Strictly encode URI components with strict-uri-encode. It uses encodeURIComponent if set to false. You probably don't care about this option.

    encode

    Type: boolean
    Default: true

    URL encode the keys and values.

    arrayFormat

    Type: string
    Default: 'none'

    • 'bracket': Serialize arrays using bracket representation:
    const queryString = require('query-string');
    
    queryString.stringify({foo: [1, 2, 3]}, {arrayFormat: 'bracket'});
    //=> 'foo[]=1&foo[]=2&foo[]=3'
    • 'index': Serialize arrays using index representation:
    const queryString = require('query-string');
    
    queryString.stringify({foo: [1, 2, 3]}, {arrayFormat: 'index'});
    //=> 'foo[0]=1&foo[1]=2&foo[2]=3'
    • 'comma': Serialize arrays by separating elements with comma:
    const queryString = require('query-string');
    
    queryString.stringify({foo: [1, 2, 3]}, {arrayFormat: 'comma'});
    //=> 'foo=1,2,3'
    
    queryString.stringify({foo: [1, null, '']}, {arrayFormat: 'comma'});
    //=> 'foo=1,,'
    // Note that typing information for null values is lost
    // and `.parse('foo=1,,')` would return `{foo: [1, '', '']}`.
    • 'separator': Serialize arrays by separating elements with a custom character:
    const queryString = require('query-string');
    
    queryString.stringify({foo: [1, 2, 3]}, {arrayFormat: 'separator', arrayFormatSeparator: '|'});
    //=> 'foo=1|2|3'
    • 'bracket-separator': Serialize arrays by explicitly post-fixing array names with brackets and separating elements with a custom character:
    const queryString = require('query-string');
    
    queryString.stringify({foo: []}, {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|'});
    //=> 'foo[]'
    
    queryString.stringify({foo: ['']}, {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|'});
    //=> 'foo[]='
    
    queryString.stringify({foo: [1]}, {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|'});
    //=> 'foo[]=1'
    
    queryString.stringify({foo: [1, 2, 3]}, {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|'});
    //=> 'foo[]=1|2|3'
    
    queryString.stringify({foo: [1, '', 3, null, null, 6]}, {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|'});
    //=> 'foo[]=1||3|||6'
    
    queryString.stringify({foo: [1, '', 3, null, null, 6]}, {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|', skipNull: true});
    //=> 'foo[]=1||3|6'
    
    queryString.stringify({foo: [1, 2, 3], bar: 'fluffy', baz: [4]}, {arrayFormat: 'bracket-separator', arrayFormatSeparator: '|'});
    //=> 'foo[]=1|2|3&bar=fluffy&baz[]=4'
    • 'none': Serialize arrays by using duplicate keys:
    const queryString = require('query-string');
    
    queryString.stringify({foo: [1, 2, 3]});
    //=> 'foo=1&foo=2&foo=3'
    arrayFormatSeparator

    Type: string
    Default: ','

    The character used to separate array elements when using {arrayFormat: 'separator'}.

    sort

    Type: Function | boolean

    Supports both Function as a custom sorting function or false to disable sorting.

    const queryString = require('query-string');
    
    const order = ['c', 'a', 'b'];
    
    queryString.stringify({a: 1, b: 2, c: 3}, {
    	sort: (a, b) => order.indexOf(a) - order.indexOf(b)
    });
    //=> 'c=3&a=1&b=2'
    const queryString = require('query-string');
    
    queryString.stringify({b: 1, c: 2, a: 3}, {sort: false});
    //=> 'b=1&c=2&a=3'

    If omitted, keys are sorted using Array#sort(), which means, converting them to strings and comparing strings in Unicode code point order.

    skipNull

    Skip keys with null as the value.

    Note that keys with undefined as the value are always skipped.

    Type: boolean
    Default: false

    const queryString = require('query-string');
    
    queryString.stringify({a: 1, b: undefined, c: null, d: 4}, {
    	skipNull: true
    });
    //=> 'a=1&d=4'
    const queryString = require('query-string');
    
    queryString.stringify({a: undefined, b: null}, {
    	skipNull: true
    });
    //=> ''
    skipEmptyString

    Skip keys with an empty string as the value.

    Type: boolean
    Default: false

    const queryString = require('query-string');
    
    queryString.stringify({a: 1, b: '', c: '', d: 4}, {
    	skipEmptyString: true
    });
    //=> 'a=1&d=4'
    const queryString = require('query-string');
    
    queryString.stringify({a: '', b: ''}, {
    	skipEmptyString: true
    });
    //=> ''

    .extract(string)

    Extract a query string from a URL that can be passed into .parse().

    Note: This behaviour can be changed with the skipNull option.

    .parseUrl(string, options?)

    Extract the URL and the query string as an object.

    Returns an object with a url and query property.

    If the parseFragmentIdentifier option is true, the object will also contain a fragmentIdentifier property.

    const queryString = require('query-string');
    
    queryString.parseUrl('https://foo.bar?foo=bar');
    //=> {url: 'https://foo.bar', query: {foo: 'bar'}}
    
    queryString.parseUrl('https://foo.bar?foo=bar#xyz', {parseFragmentIdentifier: true});
    //=> {url: 'https://foo.bar', query: {foo: 'bar'}, fragmentIdentifier: 'xyz'}

    options

    Type: object

    The options are the same as for .parse().

    Extra options are as below.

    parseFragmentIdentifier

    Parse the fragment identifier from the URL.

    Type: boolean
    Default: false

    const queryString = require('query-string');
    
    queryString.parseUrl('https://foo.bar?foo=bar#xyz', {parseFragmentIdentifier: true});
    //=> {url: 'https://foo.bar', query: {foo: 'bar'}, fragmentIdentifier: 'xyz'}

    .stringifyUrl(object, options?)

    Stringify an object into a URL with a query string and sorting the keys. The inverse of .parseUrl()

    The options are the same as for .stringify().

    Returns a string with the URL and a query string.

    Query items in the query property overrides queries in the url property.

    The fragmentIdentifier property overrides the fragment identifier in the url property.

    queryString.stringifyUrl({url: 'https://foo.bar', query: {foo: 'bar'}});
    //=> 'https://foo.bar?foo=bar'
    
    queryString.stringifyUrl({url: 'https://foo.bar?foo=baz', query: {foo: 'bar'}});
    //=> 'https://foo.bar?foo=bar'
    
    queryString.stringifyUrl({
    	url: 'https://foo.bar',
    	query: {
    		top: 'foo'
    	},
    	fragmentIdentifier: 'bar'
    });
    //=> 'https://foo.bar?top=foo#bar'

    object

    Type: object

    url

    Type: string

    The URL to stringify.

    query

    Type: object

    Query items to add to the URL.

    .pick(url, keys, options?)

    .pick(url, filter, options?)

    Pick query parameters from a URL.

    Returns a string with the new URL.

    const queryString = require('query-string');
    
    queryString.pick('https://foo.bar?foo=1&bar=2#hello', ['foo']);
    //=> 'https://foo.bar?foo=1#hello'
    
    queryString.pick('https://foo.bar?foo=1&bar=2#hello', (name, value) => value === 2, {parseNumbers: true});
    //=> 'https://foo.bar?bar=2#hello'

    .exclude(url, keys, options?)

    .exclude(url, filter, options?)

    Exclude query parameters from a URL.

    Returns a string with the new URL.

    const queryString = require('query-string');
    
    queryString.exclude('https://foo.bar?foo=1&bar=2#hello', ['foo']);
    //=> 'https://foo.bar?bar=2#hello'
    
    queryString.exclude('https://foo.bar?foo=1&bar=2#hello', (name, value) => value === 2, {parseNumbers: true});
    //=> 'https://foo.bar?foo=1#hello'

    url

    Type: string

    The URL containing the query parameters to filter.

    keys

    Type: string[]

    The names of the query parameters to filter based on the function used.

    filter

    Type: (key, value) => boolean

    A filter predicate that will be provided the name of each query parameter and its value. The parseNumbers and parseBooleans options also affect value.

    options

    Type: object

    Parse options and stringify options.

    Nesting

    This module intentionally doesn't support nesting as it's not spec'd and varies between implementations, which causes a lot of edge cases.

    You're much better off just converting the object to a JSON string:

    const queryString = require('query-string');
    
    queryString.stringify({
    	foo: 'bar',
    	nested: JSON.stringify({
    		unicorn: 'cake'
    	})
    });
    //=> 'foo=bar&nested=%7B%22unicorn%22%3A%22cake%22%7D'

    However, there is support for multiple instances of the same key:

    const queryString = require('query-string');
    
    queryString.parse('likes=cake&name=bob&likes=icecream');
    //=> {likes: ['cake', 'icecream'], name: 'bob'}
    
    queryString.stringify({color: ['taupe', 'chartreuse'], id: '515'});
    //=> 'color=taupe&color=chartreuse&id=515'

    Falsy values

    Sometimes you want to unset a key, or maybe just make it present without assigning a value to it. Here is how falsy values are stringified:

    const queryString = require('query-string');
    
    queryString.stringify({foo: false});
    //=> 'foo=false'
    
    queryString.stringify({foo: null});
    //=> 'foo'
    
    queryString.stringify({foo: undefined});
    //=> ''

    FAQ

    Why is it parsing + as a space?

    See this answer.

    query-string for enterprise

    Available as part of the Tidelift Subscription.

    The maintainers of query-string and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. Learn more.

    Install

    npm i query-string

    DownloadsWeekly Downloads

    9,360,168

    Version

    7.0.1

    License

    MIT

    Unpacked Size

    44.8 kB

    Total Files

    5

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